Secretary of State Rex Tillerson used a separate email account under the name Wayne Tracker when he was CEO of Exxon, the New York attorney general revealed in a court filing asking to get more documents.

Tillerson, whose middle name is Wayne, used the Wayne Tracker account to discuss climate change, as well as other priority matters, according to a filing in connection with a lawsuit claiming the oil giant shielded its internal findings about climate change.

He used the account to 'send and receive materials regarding important matters,' Schneiderman's office wrote in a letter seeking to force more document production.

Tillerson used the previously secret account for 'secure and expedited communications between select senior company officials and the former chairman for a broad range of business-related topics,' Exxon spokesman Alan Jeffers told Bloomberg News.

Secretary of State Rex Tillerson is revealed in a court filing to have used the name Wayne Tracker in internal emails while he was CEO of Exxon

He began the practice after his main account got too many messages, he said.

The existence in the account may have been flagged by a small batch of documents that got handed over inadvertently.

'Despite the company's incidental production of approximately 60 documents bearing the "Wayne Tracker" email address, neither Exxon nor its counsel have ever disclosed that this separate email account was a vehicle for Mr. Tillerson's relevant communications at Exxon," Senior Enforcement Counsel John Oleske wrote in the letter, CNN Money reported.

Exxon spokesman Alan Jeffers said in a statement: 'The email address, Wayne.Tracker@exxonmobil.com, is part of the company's email system and was put in place for secure and expedited communications between select senior company officials and the former chairman for a broad range of business-related topics.'

New York and Massachusetts are probing whether Exxon misled investors for years about its knowledge of whether its activities contributed to climate change.

CALL ME WAYNE: Secretary of State Rex Tillerson meets with Greece's Foreign Minister Nikos Kotzias at the State Department on Monday

New York Attorney General Eric Schneiderman's office is investigating whether Exxon misled shareholders about climate change

IT'S A GAS: Former CEO Wayne Tillerson used the name Wayne Tracker on internal company emails, a legal filing revealed

It brings yet another email controversy close to the state department, an agency that was rocked by revelations about former Secretary of State Hillary Clinton's use of a private email server and private account.

Clinton's daughter, Chelsea, was revealed to have her own email nom de plume: Diane Reynolds.

Although he has made few public statements and shielded himself from the press, Tillerson could have some sway over climate policy from his post at Foggy Bottom.

He could help shape whether the U.S. withdraws from the Paris climate accords.

The New York Times reported in 2015 that Schneiderman had begun probing whether the company shielded investors from what its own scientists had determined about the risks posed by climate change.

The internal conclusions came as the company funded outside research that was skeptical about climate change.

'If they had nothing to hide, then why the secret email account?" Jamie Henn, spokesman for the environmental group 350.org, told Bloomberg.

According to the letter to Judge Barry Ostrager, 'We write to notify the Court that Exxon Mobil Corporation (“Exxon”) has failed to comply in good faith with the subpoena issued by the New York State Office of the Attorney General (“OAG”), and this Court’s previous orders, in connection with OAG’s investigation into Exxon’s potential violations of New York consumer, business, and investor-fraud laws.'

'Exxon has continuously delayed and obstructed the production of documents from its top executives and board members,1 which are crucial to OAG’s investigation into Exxon’s touted risk- management practices regarding climate change. We respectfully request that the Court now schedule a conference to ensure Exxon’s compliance with OAG’s subpoena,' according to the letter.

'Documents relating to these email addresses should have been preserved from the outset, and should have been searched and produced prior to January 31, 2017, as part of the promised collection of management documents,' according to the letter.